Methods and devices for urethral treatment

ABSTRACT

A system and method for treating a constricted bodily lumen, for example, a urethra constricted due to BPH. The method includes a planning stage, during which an area requiring treatment is visually identified, and an execution stage during which the lumen is expanded, a cut is formed in the inner surface of the tissue defining the lumen, and an implant is deployed in the cut. The implant can be an open C-shaped ring, and can be formed of a biodegradable material, or can be removed at a selected time after implantation. The system is formed of a planning device anchorable in the lumen and constructed to facilitate location of an area to be treated, and execution device constructed to deliver an implant, to expand the lumen, to form a cut in the inner surface of tissue defining the lumen, and to release the implant for deployment into the cut.

RELATED APPLICATION/S

This application is related to commonly owned International ApplicationIL 2010/000229, filed 21 Mar. 2010, and published as WO/2010/106543 on23 Sep. 2010 (herein referred to as the '229 application), and toInternational Application IL2012/050094, filed 15 Mar. 2012, andpublished as WO2012/123950 on 20 Sep. 2012 (herein referred to as the'094 application”). The content of both the '229 and '094 are;incorporated by reference herein as if fully set forth.

This application is also based on and claims priority to U.S.Provisional Application 61/783,257, file 14 Mar. 2013, the content ofwhich is incorporated by reference herein as if fully set forth.

FIELD OF THE INVENTION

The present invention, in some embodiments thereof, relates to systemsand methods for treatment of intra-body lumens, and, more particularly,but not exclusively, to methods and devices for dilating and/orassisting in dilation and/or maintaining dilation of the urethra torelieve obstruction resulting, for example from benign prostatichyperplasia (BPH).

Benign Prostatic Hypertrophy (BPH)

It is common for the prostate gland to become enlarged as a man ages. Asa male matures, the prostate goes through two main periods of growth,first early in puberty, and then again at around age 25, when the growthbegins again, and continues on through life. One of the effects of thiscontinued growth can be pressure on the urethra, the passage throughwhich urine passes from the bladder and the penis.

The urethra is surrounded by the prostate for part of its length. Withinthe confines of the prostate, the urine flows through a passage having agenerally triangular cross-section. As the prostate enlarges, the layerof tissue surrounding the prostate restricts the prostate from expandingoutward, causing the prostate to constrict the urethral passage. Thecondition of an enlarged, non-cancerous prostate is called benignprostatic hyperplasia (BPH).

Though the prostate continues to grow during most of a man's life, BPHrarely causes symptoms before age 40, but more than half of men in theirsixties and as many as 90 percent in their seventies and eighties havesome symptoms. BPH can make it difficult to completely empty thebladder, and is associated with other urinary system problems well knownin the medical field.

Current Treatment Techniques

Men who have symptoms associated with BPH usually need some kind oftreatment at some time. Although the need for treatment is not usuallyurgent, doctors generally advise treatment once the problems becomebothersome or present a health risk.

The most commonly used treatments for BPH include drug therapy,minimally invasive mechanical treatment, and surgery.

Among the drugs approved, for example, by the U.S. FDA, are Finasteride(Proscar), dutasteride (Avodart), terazosin (Hytrin), doxazosin(Cardura), tamsulosin (Flomax), and alfuzosin (Uroxatral). These drugsact by relaxing the smooth muscle of the prostate and bladder neck toimprove urine flow and to reduce bladder outlet obstruction. Use offinasteride and doxazosin together has also been found to be moreeffective than using either drug alone.

Drug treatment may only be partially effective in some cases.Researchers have therefore developed several mechanical procedures thatrelieve BPH symptoms but are less invasive than conventional surgery.These include transurethral microwave thermotherapy (TUMT), which usesmicrowaves to heat and destroy portions of prostate tissue,transurethral needle ablation (TUNA), which employs low-levelradio-frequency energy delivered through twin needles to burn awayselected regions of the enlarged prostate, and water-inducedthermotherapy, which uses heated water to destroy portions of prostatetissue. The use of ultrasound waves to destroy prostate tissue is alsoundergoing clinical trials in the United States.

Urethral stents have also been employed in some instances, with varyingdegrees of effectiveness.

Surgical removal of part of the prostate, thereby reducing pressureagainst the urethra is often regarded as the best long-term solution forpatients with BPH. Among the types of surgery commonly employed istransurethral surgery which requires no external incision. Suchprocedures include transurethral resection of the prostate (TURP), bywhich prostate tissue is removed, transurethral incision of the prostate(TUIP), by which the urethra is widened by making a few small cuts inthe bladder neck where the urethra joins the bladder, and in theprostate gland itself, and laser induced prostate tissue removal.

In the few cases where transurethral surgical procedures are notindicated, open surgery, which requires an external incision, may beused.

The previously mentioned '229 International Application teaches dilatinga constricted urethra by use of a balloon catheter or other expandabledilation unit and implanting a C-shaped or ring-like open loop into acut formed in the inner surface of the prostate surrounding the urethrawithin the constricted area to maintain the dilation.

Other relevant prior art includes U.S. Pat. Nos. 7,004,965, 8,145,321,and 7,632,297, and Published U.S. patent applications 2006/0173517,2005/0137716, 2010/0100195, and 2010/0130815.

SUMMARY OF THE INVENTION

According to an aspect of some embodiments of the invention, there isprovided a system for treatment of a constricted intrabody lumencomprising a planning device for performing a planning stage of thetreatment including an anchoring unit, and a set of reference markersconfigured for identifying one or more areas for treatment, and

a device for executing the treatment including a dilation unit includingan expandable element to enlarge the lumen in the area to be treated, animplant carrier releasably connectable to an implant for delivery to thearea to be treated, and a cutter including a blade positionable to forma cut in the inner surface of the tissue surrounding the area to betreated to receive the implant.

Optionally, the reference markers are configured so that treatment areascan be visually identified using an optical device inserted in thelumen.

Optionally, the lumen is a urethra that is constricted due to BPH andthe anchoring element is shaped and sized to lodge in the neck of abladder.

Optionally, the anchoring unit includes an expandable anchoring elementand a delivery element configured to expand the anchoring element.Optionally, in some embodiments, the reference markers are carried nearthe distal end of the delivery element for the anchoring element.Optionally, the anchoring element is a balloon that is substantiallytoroidal in shape upon inflation, and the delivery element is a shaftincluding a fluid passage connectable to a source of inflation fluid.Optionally, the dilation unit delivery element is comprised of twoconcentric tubes partially attached together at least distally, and thefluid path is defined by a substantially annular passage between the twotubes.

Optionally, according to some embodiments, the anchoring element and/orthe dilation element is self-expanding, and a delivery shaft is providedto release the respective self-expanding element for expansion.

According to some embodiments, the cutter is comprised of an implantcarrier portion configured to engage releasably with an implant, and theexecution device further comprises a release unit to separate theimplant from the carrier portion of the cutter.

According to some embodiments, the implant carrier is comprised of anelongated pin that includes a projection at its distal end to which animplant is releasably attachable for delivery. Optionally, the pin iscoupled to an actuator configured to pull the pin proximally todisconnect the implant from the projection. Optionally, the projectionis sized and positioned to engage a hole or a loop at one end of animplant.

According to some embodiments, the cutter is rotatable, and the cutterblade is comprised of a proximal portion and a distal portion separatedby a resilient hinge area; so that the blade assumes a generallyL-shaped operating configuration with its distal end in contact with thesurface of the tissue surrounding the lumen to form a cut as the cutteris rotated.

According to some embodiments, the cutter blade is delivered to thetreatment area in a retractable outer sheath which also carries thedilation unit and the implant carrier and release mechanism, and theblade is in a delivery configuration in the outer sheath and bladeassumes its L-shaped operating configuration when the outer sheath isretracted.

According to some embodiments, the cutter includes a delivery tube forthe blade and a pusher wire coupled to the proximal end of the blade topush it distally out of its delivery tube so that it assumes itsoperating configuration and to pull the blade proximally to retract theblade back into the delivery tube for withdrawal of the execution devicefrom the lumen. According to some embodiments, the pusher wire isconnectable to a diathermy machine or a piezoelectric transducer toprovide electric or electromechanical energy to form the cut for theimplant.

According to some embodiments, there is provided a mechanism operable toretract the cutter delivery tube proximally from the blade so the bladeemerges from the delivery tube and assumes its operating configuration,and to extend the delivery tube distally so that the blade is receivedback within the delivery tube for withdrawal of the execution devicefrom the lumen.

According to an aspect of some embodiments of the invention, variousparts of the system are interchangeable. In some embodiments, anoperating handle configured for connection to both the planning andexecution stage devices.

According to some embodiments, separate operating handles provided forconnection to the planning and execution stage devices to control thefunctions of the respective stages.

According to some embodiments, the planning stage device anchoring unitis configured to be separated from its operating handle and coupled tothe execution stage device during the execution stage. Optionally, theexecution device includes a dedicated anchoring unit. Optionally, theexecution stage anchoring unit includes a set of position referencemarkers at a proximal end thereof positionally correlated with the setof reference markers at the distal end of the planning stage anchoringunit.

According to some embodiments, the planning and execution devices areintegrated in a single unit.

According to some embodiments, the planning device includes a second setof reference markers at a proximal end of the anchoring element deliveryelement positionally correlated with the set of markers at the distalend of the delivery tube, relative to which the deployment locationsidentified during the planning stage are located during the executionstage.

According to some embodiments, a tensioning mechanism is provided forapplying a selectable and repeatable proximally directed force to theanchoring element. Optionally, the tensioning mechanism is comprised inan operating handle for the planning stage device, and the planningstage operating handle is connectable to the execution stage device.Optionally, the planning and execution stage devices each includeseparate dedicated tensioning mechanisms in operating handles for therespective devices.

Optionally, the tensioning mechanism comprises a compression spring, aguide element on which an actuator for the tensioning mechanism ismoveably mounted, and a locking element that connects the guide elementto a delivery tube for the anchoring element so that a proximallydirected force applied to the tensioning mechanism is transferred to theanchoring element delivery element.

According to some embodiments, the dilation unit is comprised of aplurality of longitudinally extending balloons disposed in a generallycircular pattern.

According to some embodiments, the dilation unit is rotatable and theimplant carrier, the implant release mechanism, and the cutter arecoupled to the dilation unit and are rotatable thereby. Optionally, theexecution device further includes a rotation mechanism for manuallyrotating the dilation unit. Alternatively, the rotation mechanism ismotor-operated.

According to an aspect of some embodiments of the invention, the systemprovides the capability for delivering deploying multiple implants.According to some embodiments, the implant carrier is configured todeliver a plurality of implants simultaneously, and to release theimplants simultaneously or one at a time.

According some embodiments, cutter includes a plurality of axiallyspaced blades configured to form a plurality of cuts simultaneously orone at a time.

An aspect of some embodiments of the invention relates to theconstruction of an operating handle for the execution stage device.According to some embodiments, the operating handle includes a mechanismconfigured to retract an outer sheath, a mechanism configured to rotatea cutter, a mechanism configured to provide fluid-tight delivery ofinflation fluid to a rotatable delivery element for a dilation element,a mechanism configured to release an implant from a carrier; and amechanism configured to push an implant out of the outer sheath.

According to some embodiments, a tensioning mechanism is provided toapply proximally directed force to an anchoring balloon element for thesystem. Optionally, there is also provided a pressure sensor connectableto an inflation tube for the anchoring balloon; and a pressure indicatorthat is responsive to an increase of the pressure in the anchoringelement inflation tube when tension is applied during the planning stageto provide a visual and/or aural indication when the same tension isapplied during the execution stage. Optionally, there is also provided aholder for the execution stage operating handle attachable to a surgicaltable that maintains tension applied during the execution stage withouthuman intervention.

According to some embodiments, wherein the dilation unit is rotatable,there is provided an inflation port configured to provide inflationfluid for the dilation balloon while the dilation unit rotates.Optionally, the inflation port comprises a body, a tubular passage, oneend of which is coupled to the body, and the other end terminates in afitting connectable to a source of inflation fluid, end sections onproximal and distal ends of the body including portions formed of aresilient material, that provide fluid-tight rotatable seal for thedilation unit inflation tube.

An aspect of some embodiments, relates to a method for treating a bodilylumen comprising identifying one or more areas of the lumen requiringtreatment during a planning stage using a planning device inserted inthe lumen, delivering an implant in a compressed condition fordeployment at the treatment area, expanding the lumen in the treatmentarea, forming a cut in the inner surface of the tissue surrounding theconstricted area, and inserting an implant into the cut to maintain theexpansion of the lumen According to some embodiments, delivery of theimplant, expanding the lumen, forming the cut, and inserting the implantinto the cut are performed using an execution device inserted into thelumen after an area requiring treatment has been identified.

Optionally, forming the cut includes connecting a cutter comprised inthe execution device to a diathermy machine or a piezoelectrictransducer to provide a source of electrical or electromechanicalenergy. Optionally, the cut is formed by rotating the cutter around aninner surface of the tissue surrounding an area of the lumen requiringtreatment.

According to some embodiments, the implant is removed after apredetermined time. Alternatively, the implants are formed of a materialthat is biodegradable.

According to some embodiments, the lumen to be treated is a urethraconstricted due to BPH, and the implant is deployed in the inner surfaceof the prostate defining the portion of the urethra within the prostate.Optionally, the implant is an open generally C-shaped ring. Optionally,for treatment of BPH, the implant is released for deployment with itsopen side facing toward the rectum wall.

According to some embodiments, the planning stage includes anchoring theplanning device at a desired location in the lumen using an expandableanchoring element. Optionally, desired deployment locations areidentified visually during the planning stage relative to a first set ofposition reference markers comprised in the positioning unit, using anoptical device inserted into the lumen and the identified deploymentlocations are determined during the execution stage relative to a secondset of position reference markers visible outside the lumen andpositionally correlated with the first set of position referencemarkers.

According to some embodiments, the anchoring and dilation elements areballoons, and are inflated using a liquid as an inflation fluid.

According to some embodiments, the positioning unit remains in the lumenafter completion of the planning stage; and is connected to thepositioning unit to the execution device for use during the executionstage.

According to some embodiments, two or more implants are delivered to thearea to be treated simultaneously, the cuts are formed for all of theimplants simultaneously, and

all the implants are deployed simultaneously.

Optionally, two or more implants are delivered simultaneously using asingle unit for delivery of all the implants. Alternatively, or eachimplant is delivered by a separate device, and further comprisingforming cuts for the implants at the time the respective implants aredelivered.

According to some embodiments, tension is applied to lodge an anchoringballoon firmly in the neck of the bladder during the planning andexecution stages for treatment of BPH.

According to some embodiments, tension is applied during the executionstage is selected in reference to visible markers on an operating handlefor the execution stage device or according to an audible or visualsignal provided by a pressure indicator according to tension appliedduring the planning stage. Optionally, the execution stage device isattached to a holder on a surgical table to maintain tension appliedduring the execution stage.

Optionally according to some embodiments, the cut is formed by a cutterdelivered to the implantation site, or by the implant, or by cooperationof a cutter and the implant.

Optionally, according to some embodiments, the implant-receiving cut isclosed after deployment of the implant by application of an adhesive, orby a clamp, or by a suture.

Unless otherwise defined, all technical and/or scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which the invention pertains. Although methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of embodiments of the invention, exemplarymethods, and/or materials are described below. In case of conflict, thepatent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and are notintended to be necessarily limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the invention are herein described, by way ofexample only, with reference to the accompanying drawings. With specificreference now to the drawings in detail, it is stressed that theparticulars shown are by way of example and for purposes of illustrativediscussion of embodiments of the invention. In this regard, thedescription taken with the drawings makes apparent to those skilled inthe art how embodiments of the invention may be practiced.

In the drawings:

FIG. 1A is an illustration of a bladder, a normal prostate and a part ofa urethra;

FIG. 1B illustrates constriction of the urethra due to an enlargedprostate;

FIG. 2 is a conceptual illustration of apparatus for treating BPHaccording to some embodiments of the invention;

FIG. 3A is a pictorial perspective view of a device for implementing theplanning stage according to some embodiments of the invention;

FIG. 3B is an enlarged perspective view of an anchoring element for thedevice of FIG. 3A according to some embodiments;

FIG. 3C is a sectional perspective view of FIG. 3B according to someembodiments;

FIG. 3D is a perspective view seen generally for one side and fromabove, of the handle body shown in FIG. 3A emphasizing features relevantto a tensioning mechanism for the anchoring element according to someembodiments;

FIG. 3E is an exploded view of FIG. 3D;

FIG. 3F is an enlarged side view of a handle guide which is part of thetensioning mechanism of FIG. 3D according to some embodiments;

FIG. 3G is a perspective end view of a tube lock cylinder which is partof the tensioning mechanism according to some embodiments

FIG. 3H is an end elevation view of the assembled tensioning mechanismof FIGS. 3D-3G;

FIG. 4A is side elevation view of an execution stage device according tosome embodiments;

FIG. 4B is an enlarged side perspective of the distal end of theexecution stage device shown in FIG. 4A according to some embodiments;

FIG. 4C is an enlarged side perspective view of an exemplary implant andan implant release mechanism according to some embodiments;

FIG. 4D is a perspective view of an exemplary cutting blade comprised inthe execution stage device shown in FIGS. 4A and 4B according to someembodiments;

FIG. 5A is a side elevation of an exemplary operating handle for anexecution stage device with a cover of the handle removed showing theinternal parts according to some embodiments;

FIG. 5B is a top view of the operating handle shown in FIG. 5A;

FIG. 5C is an enlarged view of part of FIG. 5A showing details of theconstruction of exemplary operating mechanisms within the executionstage operating handle according to some embodiments;

FIG. 5D is an exploded view of the tensioning mechanism shown in FIG.5C;

FIG. 5E is a perspective view of a marker element comprised in thetensioning mechanism shown in FIGS. 5A through 5D according to someembodiments;

FIG. 5F is an enlarged perspective view showing the manner in which themarker element shown in FIG. 5E cooperates with tensioning markers onthe execution stage operating handle;

FIG. 5G is a schematic block diagram of an alternative way of indicatingtension according to some embodiments;

FIG. 5H side elevation of an exemplary outer sheath retraction mechanismfor the operating stage device according to some embodiments;

FIG. 5I is a proximal end elevation view of the sheath retractionmechanism shown in FIG. 5H;

FIG. 5J is an enlarged side view of a dilation unit inflation port for arotatable dilation unit inflation tube according to some embodiments;

FIG. 5K is a side elevation view of an implant release trigger mechanismcomprised in the execution stage device according to some embodiments;

FIG. 5L is a perspective view of a pull handle comprised in the implantrelease trigger mechanism shown in FIG. 5L according to someembodiments;

FIG. 5M is a side perspective view of a guide flange comprised in themechanism shown in FIG. 5K according to some embodiments;

FIG. 5N is side elevation of an implant pusher for the execution stagedevice according to some embodiments;

FIG. 5O is a perspective view of the implant pusher shown in FIG. 5N;

FIGS. 6A and 6B are a flow chart showing the elements of an exemplarymethod of treating a constricted lumen according to some embodiments;

FIGS. 7A-7D are illustrations of apparatus in configurationscorresponding to several elements of the method of FIGS. 6A and 6B; and

FIG. 8 is a pictorial schematic illustration of an arrangement forsimultaneous deployment of several implants.

DETAILED DESCRIPTION OF THE INVENTION Preliminary ClarificationRegarding the Terms “Distal” and “Proximal”

Preliminarily, for purposes of clarity, it should be noted that theterms “proximal” and “distal” which are used herein are conventionallydefined relative to a point of reference. For example, when the urethrais constricted in more than one location, the constriction closest tothe bladder would generally be referred to as “proximal” to the bladder”and the constriction furthest from the bladder will be referred to as“distal”. On the other hand, with reference to a surgical apparatus, thedirections are usually referred to in the opposite way so that the partclosest to the surgeon is considered the proximal end while the oppositeend is regarded as the distal end. The reference point will be statedwhen either term is used herein if not completely clear from thecontext.

Introductory Overview

The present invention, in some embodiments thereof, relates to systemsand methods for treatment of intra-body lumens. By way of a non-limitingexample, some embodiments relate specifically to systems and methods fordilating and/or assisting in dilation and/or maintaining dilation of theurethra to relieve obstruction resulting, for example, from benignprostatic hyperplasia (BPH).

Broadly stated, the systems and methods are designed to implement atwo-stage procedure comprised of a planning stage during which an areaor areas to be treated are identified, and an execution stage duringwhich the lumen is dilated, and one or more implants are deployed tohelp maintain the patency of the dilated lumen.

To this end, an aspect of some embodiments of the invention relates tothe construction of a device for implementing the planning stage, Insome embodiments, the planning stage device includes a set of referencemarkers relative to which one or more areas for treatment can beidentified, optionally, the planning device includes an anchoring unitformed of an anchoring element, and a delivery element for the anchoringelement. Optionally, the anchoring element is a balloon and the deliveryelement provides a fluid path for inflation fluid. Optionally, theinflated anchoring balloon is toroidally shaped after it is inflated.

Optionally the anchoring element is self-expanding and the deliveryelement is configured to release the anchoring element (for example,from a sheath) for expansion.

Optionally, the reference markers are carried by the delivery elementfor the anchoring element.

An aspect of some embodiments of the invention relates to theconstruction of a device for implementing the execution stage.

In some embodiments, the execution device includes a dilation unit toenlarge the lumen in an area to be treated, a carrier to releasablydeliver an implant to the area to be treated, and a cutter including ablade positionable to form a cut in the inner surface of the tissuesurrounding the area to be treated.

Optionally, the dilation unit includes an expandable element and adelivery element for the expandable element. Optionally, the expandableelement is a balloon and the delivery element provides a fluid path forinflating the balloon. Optionally, the dilation balloon delivery elementis comprised of two concentric tubes partially attached together atleast distally, and the fluid path is defined by a substantially annularpassage between the two tubes.

Optionally, the expandable element is self-expanding, and the deliveryelement is constructed to release the expandable element (for example,from a sheath) so it can expand.

According to some embodiments, the cutter includes a portion configuredto deliver the implant. Optionally the implant carrier portion of thecutter is a projection, for example, a pin, extending from the cutterblade, configured to engage releasably with a complementary portion ofan implant. Optionally, the complementary portion of the implant is ahole. Optionally, it is a wire loop. Optionally, in such embodiments, arelease mechanism is provided as part of the execution device toseparate the implant from the carrier portion of the cutter.

According to some embodiments, delivery and release of the implant isprovided for by an integrated carrier and release mechanism. Optionally,in such embodiments, the implant is attached to a projection at a distalend of a release pin for delivery. Optionally, the projection extendsthrough a hole at one end of the implant. Optionally, the projectionextends though a loop attached at the end of the implant.

Optionally, the pin extends to a release mechanism, for example, in anoperating handle for the execution device. Optionally, the releasemechanism is operable to retract the pin proximately to separate it fromthe implant.

Optionally, a release mechanism as just described may be employed inembodiments of the invention in which the implant is carried by thecutter.

Optionally, in embodiments employing a unitary implant and releasemechanism and in embodiments in which the implant is delivered by thecutter, the release mechanism may be configured to retract the cutterblade proximally when the release pin is pulled proximally.

An aspect of the invention relates to the construction of the cutter andthe cutter blade. According to some embodiments, one or more of thefeatures described below may be incorporated in cutters comprised insystems according to the invention:

-   -   (a) the cutter is rotatable;    -   (b) the cutter blade is comprised of a proximal portion and a        distal portion separated by a resilient hinge area;    -   (c) the cutter is configured so that the distal portion of the        blade is delivered to a treatment site folded proximally along        the proximal portion, and is releasable to so it assumes a        generally L-shaped operating configuration with its distal end        in contact with the surface of the tissue surrounding the lumen        to form a cut as the cutter is rotated;    -   (d) a delivery tube for the blade and a pusher wire configured        to engage the proximal end of the blade to push it distally out        of its delivery tube so that it assumes its operating        configuration and to pull the blade proximally to retract the        blade back into the delivery tube for withdrawal of the        execution device from the lumen;    -   (e) A delivery tube for the blade and a mechanism operable to        retract the cutter delivery tube proximally from the blade so        the blade emerges from the delivery tube and assumes its        operating configuration, and to extend the delivery tube        distally so that the blade is received back within the delivery        tube for withdrawal of the execution device from the lumen;    -   (f) the cutter is connectable to a source of electric or        electromechanical energy to form the cut for the implant;    -   (g) the source of energy is a diathermy machine or a        piezoelectric transducer;    -   (h) the blade is formed of a resilient material;    -   (i) a hinge is formed in an area between the proximal and a        distal parts by heat-treating the area;    -   (j) the blade is folded at the hinge area in the tube during        delivery to the treatment area;    -   (k) the blade is delivered in an outer sheath along with an        implant carrier and release mechanism and a dilation unit in a        delivery configuration in which the distal part of the blade is        bent distally, for example, at an angle in the range of about 45        to about 90 degrees distally relative to the direction        corresponding to its cutting configuration, so that when the        outer sheath is retracted, the distal part of the blade assumes        its cutting configuration;    -   (l) the distal part of the cutter blade is of sufficient width        in a direction tangential to the cutting direction that it does        not deform while the cut is being made;    -   (m) the thickness of the distal part of the cutter blade in a        longitudinal direction of the lumen is sufficient to accommodate        the width of the implant, but not so thick as to interfere with        it being folded for release from the lumen;    -   (n) The length of the distal part of the blade is sufficient for        formation of a cut within which the implant can be fully seated.

An aspect of some embodiments of the invention pertains tointerchangeability of certain parts of the planning and execution stagedevices. In some such embodiments, a single operating handle isconfigured for connection to both the planning and execution stagedevices to control their respective functions. Alternatively, separateoperating handles are provided for the planning and execution stagedevices.

In some embodiments, the planning stage device anchoring unit isconfigured to be separated from its operating handle and coupled to theexecution stage device during the execution stage. Alternatively, theexecution device includes a dedicated anchoring unit. Optionally, theexecution stage anchoring unit includes a set of position referencemarkers at a proximal end correlated with the set of reference markersat the distal end of the planning stage anchoring unit.

In some embodiments, the planning and execution devices are integratedin a single unit.

In embodiments for which the anchoring unit is coupled to the executiondevice during the execution stage, there is provided a second set ofreference markers are at the proximal end of the anchoring elementdelivery element that are positionally correlated with the set ofmarkers at the distal end.

In some embodiments, the planning stage device and the execution stagedevice each includes a tensioning mechanism for applying a selectableand repeatable proximally directed force to the anchoring element.Optionally, the execution device does not include a dedicated tensioningmechanism. In such embodiments, a tensioning mechanism for the executiondevice is provided by connecting an operating handle for the planningdevice to an operating handle for the execution device.

In some embodiments, the tensioning mechanism(s) are comprised in anoperating handle. Optionally, the tensioning mechanism(s) include one ormore of the following features:

-   -   (a) a compression spring;    -   (b) a guide element on which an actuator for the tensioning        mechanism actuator is moveably mounted;    -   (c) a locking element inside the guide element that connects the        guide element to a delivery tube for a delivery element for an        anchoring element;    -   (d) a locking screw that passes through a passage in the guide        element and immobilizes the anchoring element delivery element        relative to the guide element when the locking screw is        sufficiently tightened and releases the delivery element when        the screw is sufficiently loosened;    -   (e) the locking element is a resilient tube-like structure, for        example a cylinder formed of a resilient material with a        longitudinal slit so that it can be compressed by the locking        screw;    -   (f) the inner tube of the dilation balloon inflation element is        sized and configured to receive the anchoring element delivery        element therein;

According to some embodiments, one or more of the following features mayalso be included in an operating handle for the execution device:

-   -   (a) the dilation unit is comprised of a plurality of        longitudinally extending balloons disposed in a generally        circular pattern and a delivery element for the balloons that        includes a fluid passage connectable at its proximal end to a        source of inflation fluid to inflate the dilation balloons;    -   (b) the dilation unit, the implant carrier and release        arrangement, and the cutter are delivered to the treatment site        in a retractable outer sheath;    -   (c) the dilation unit is rotatable and the implant carrier, the        implant release mechanism, and the cutter are rotatable thereby;    -   (d) the implant carrier is configured to deliver a plurality of        implants simultaneously, and to release the implants        simultaneously or one at a the same time;    -   (e) the cutter includes a plurality of axially spaced blades        configured to form a plurality of cuts simultaneously or one at        a time;    -   (f) a mechanism configured to retract an outer sheath;    -   (g) a mechanism configured to release a cutter blade to an        operating position;    -   (h) a mechanism configured to provide fluid-tight delivery of        inflation fluid to a rotatable delivery element for a dilation        element;    -   (i) a mechanism configured to release an implant from a carrier        for deployment;    -   (j) a mechanism configured to push an implant out of the outer        sheath;    -   (k) a pressure sensor connectable to an anchoring element        inflation tube for an anchoring balloon and a pressure        indicator, the pressure indicator being responsive to an        increase of the pressure in the anchoring element inflation tube        when tension is applied during the planning stage to provide a        visual and/or aural indication when the same tension is applied        during the execution stage;    -   (l) a holder for the execution stage operating handle attachable        to a surgical table that maintains tension applied during the        execution stage without human intervention;    -   (m) An inflation port configured to provide inflation fluid for        the dilation balloon while the dilation unit rotates.

In some embodiments, feature (i) above optionally retracts the cutterproximally when the implant is released.

In some embodiments, the inflation port (feature (m) above) includes abody, a tubular passage, wherein one end of the passage is coupled tothe body, and the other end terminates in a fitting connectable to asource of inflation fluid; end sections on proximal and distal ends ofthe body including portions formed of a resilient material, wherein thedistal end section is coupled to the dilation unit inflation tube andprovides a fluid-tight rotatable seal for the dilation unit inflationtube.

In some embodiments of the invention, there is provided a mechanism forclosing the implant-receiving cut by application of an adhesive, or by aclamp, or by a suture.

An aspect if some embodiments of the invention pertain to a methodtreating a constricted bodily lumen such as a urethra constricted due toBPH.

Optionally, in some embodiments, the method involves identifying one ormore areas of the lumen requiring treatment during a planning stage,delivering an implant in a compressed condition for deployment at thetreatment area, expanding the lumen in the treatment area, forming a cutin the inner surface of the tissue surrounding the constricted area; andinserting an implant into the cut to maintain the expansion of thelumen.

Optionally, delivery of the implant, expanding the lumen, forming thecut, and inserting the implant into the cut are performed using anexecution device inserted into the lumen after an area requiringtreatment has been identified, and wherein expanding the lumen isperformed using a dilation unit comprised in the execution device, andidentifying areas to be treated is performed using a planning deviceincluding a positioning unit inserted in the lumen.

Optionally, forming the cut includes rotating a cutter blade around theinner surface of the tissue defining the lumen.

Optionally, forming the cut includes connecting a cutter blade theexecution device to a source of electrical or electromechanical energy.Optionally the source of electrical or electromechanical energy is adiathermy machine or a piezoelectric transducer.

Optionally, according to some embodiments, the implant is removed aftera predetermined time. Alternatively, the implant is formed of a materialthat is biodegradable.

Optionally, the implant is an open generally C-shaped ring.

Optionally, in embodiments, for which the method is applied to treatmentof BPH, the implant is released for deployment with its open side facingthe rectum wall .

In some embodiments, the planning device is comprised of an expandableanchoring element and a delivery element for the anchoring element, andthe method includes anchoring the planning device at a desired locationin the lumen using the anchoring element. Optionally, desired deploymentlocations are identified visually during the planning stage relative toa first set of position reference markers comprised in the positioningunit, using an optical device inserted into the lumen and the identifieddeployment locations are identified during the execution stage relativeto a second set of position reference markers visible outside the lumenand positionally correlated with the first set of position referencemarkers.

According to some embodiments, the dilation unit is comprised of aballoon and a delivery tube for the balloon, and the constriction isexpanded by inflating the dilation balloon through its delivery tube. Insome embodiments, the anchoring element is a balloon, and the anchoringand dilation balloons are inflated using a liquid as an inflation fluid.

According to some embodiments, the positioning unit remains in the lumenafter completion of the planning stage and is coupled to the executiondevice for use during the execution stage.

An aspect of the invention pertains to deployment of multiple implants.In some embodiments, this is accomplished by delivering two or moreimplants to the area to be treated at one time, forming cuts for all ofthe implants at the same time, and releasing all of the implants fordeployment simultaneously. Optionally, the implants are delivered one ata time, using a single unit for delivery of all the implants or aseparate device for each implant, and cuts for the implants are formedat the time the respective implants are delivered.

According to some embodiments, the tension applied during the executionstage is selected in reference to visible markers on an operating handlefor the execution stage device or according to an audible or visualsignal provided by a pressure indicator according to tension appliedduring the planning stage.

In some embodiments, the execution stage device is attached to a holderon a surgical table to maintain tension applied during the executionstage.

In some embodiments, the cut is optionally formed by a cutter deliveredto the implantation site, or by the implant, or by cooperation of acutter and the implant.

In some embodiments, the method includes closing the implant-receivingcut after deployment of the implant by application of an adhesive, or bya clamp, or by a suture.

Treatment Environment

FIG. 1A illustrates schematically a male bladder 100, a portion of theurethra 102, and a normal prostate 104 surrounding the urethradownstream of the bladder.

In contrast, FIG. 1B illustrates the effect of enlargement of theprostate due to BPH (Benign Prostatic Hyperplasia). As may be seen, theenlargement of prostate 106 constricts the portion of urethra 108passing through it as well as the neck 110 of bladder 100, resulting inthe various problems discussed above. The embodiments to be describedbelow are concerned with apparatus and methods for dilation of theconstricted region, and deployment of an implant within the enlargedpart of the prostate to help maintain the dilation.

As will be appreciated, constrictions of other bodily lumens aresimilarly treated.

Conceptual Illustration of Apparatus For Treating BPH:

FIG. 2 shows conceptually a portion 200 of a system for treating aconstructed lumen according to some embodiments of the invention. Usingtreatment of BPH as an exemplary embodiment, the illustrated portion ofsystem 200 is deployed in a urethra defined by an inner surface 202 ofan enlarged prostate 204. System 200 includes a dilation unit comprisedof an expandable dilation element 206 carried at the distal end of adelivery element 208. Dilation element 206 is expandable to dilate theconstricted urethra, and an implant 210. In some embodiments, dilationelement 206 is a balloon and delivery element 208 is tube by whichballoon is delivered and through which it is inflated.

In the illustrated construction, an implant 210 is carried on dilationelement 206 for insertion in a cut formed on inner surface 202 ofprostate 204 to help maintain the patency of the dilated urethra.

For simplicity of illustration and discussion at this stage, dilationunit 206 is shown as a single balloon. However, as explained below, insome embodiments, the dilation unit may be comprised of multiple smallballoons positioned around delivery tube 208. Other forms of dilationelements, for example, resilient structures that are self-expanding, arealso possible.

Distally of dilation unit 206, there is an anchoring element 212, forexample, a balloon, carried on a delivery tube 214 received in dilationunit delivery tube 208. Delivery tube 214 also serves as a fluid pathfor inflation of balloon 212. In use, anchoring balloon 212 ispositioned in the neck 216 of bladder 218 and tension is applied todelivery tube 214 at its proximal end to retain balloon 212 firmly inplace. As described below, markers (not shown) on delivery tube 214provide a reference to help locate an area or areas at which one or moreimplants 210 will be deployed.

Generally stated, implant 210 is inserted in a cut, for example, a slotor groove formed in prostate surface 202. For this purpose, a cutterdevice (not shown for simplicity of illustration) is also delivered withdilation unit 206 and implant 210. To facilitate deployment, a workingchannel (not shown) may be provided by a standard cystoscope orresectoscope through which system 200 is inserted.

It should be understood that FIG. 2 is only intended as a generalizedconceptual illustration and that exemplary embodiments will beillustrated and described in detail below. It should also be understoodthat dilation element 206 and anchoring element 212 are shown inflatedin FIG. 2, but that they are delivered to the treatment siteun-inflated.

Exemplary Planning Stage Device:

As mentioned above, a basic concept according to some embodiments of theinvention involves separation of the implant procedure into two stages:a planning stage during which one or more areas constricted by theenlargement of the tissue surrounding the lumen are identified, and anexecution stage during which the lumen is dilated and one or moreimplants are delivered and installed in the tissue surrounding the lumento help maintain the dilation. In some embodiments according to thisconcept, each stage is performed using separate implementation devices.Preferably, however, a positioning catheter that is part of the planningdevice is also used during the execution stage.

Optionally, an operating handle that is part of the planning device, mayalso be used for both stages, as described below.

Optionally, entirely separate devices are used for each stage.Alternatively, a single operating handle can be used for both stages. Asa further option, the planning and execution stages can be combined in asingle unit.

Construction of Exemplary Embodiments Planning Stage Device

FIGS. 3A-3G illustrate various features of an exemplary device 300 forimplementing the planning stage according to some embodiments of thetwo-stage concept. FIG. 3A is a perspective view of device 300 as awhole. The device is comprised of a planning catheter 304, and anoperating handle 302 for planning catheter 304, Planning catheter 304 iscomprised of an expandable anchoring element 306 that helps position theplanning catheter at a desired location in the lumen, and a deliveryelement 308 formed of stainless steel, or a rigid biocompatible polymerthat carries anchoring element 306 at its distal end.

In some embodiments, anchoring element 306 is a balloon that is expandedby inflation fluid provided through an interior passage in a tubeforming delivery element 308. In some embodiments related to treatmentof BPH, balloon 306 is shaped and sized so it fits firmly inside bladderneck 110 after it is inflated and when delivery tube 308 is pulledproximally as described below.

FIGS. 3B and 3C illustrate the construction of one desirable embodimentof balloon 306 in perspective and sectional views. Notably, balloon 306,when inflated, is toroidally shaped with delivery tube 308 passingthrough the balloon and attached to it by a suitable adhesive at points309 a and 309 b. Balloon 306 may be fabricated with the desired inflatedshape, or can be spherical, and formed to the required shape by locatingadhesive points 309 a and 309 b sufficiently close together.

Delivery tube 308 is sealed at its distal end 311, and is provided withan opening or perforations 313 inside the balloon through which theballoon is inflated and deflated.

The toroidal shape illustrated is advantageous, as compared to aspherical or other convex shape at the bladder neck in that it allows adilation unit comprised in the execution stage device described below tobe positioned closer to the bladder neck if implantation is indicated atthat location.

As shown in FIG. 3A, the proximal end 310 of delivery tube 308 extendsout through the proximal end of planning catheter operating handle 302and terminates in a fitting 312 that serves as an inlet for inflationfluid provided, for example, by a hand operated syringe, a source ofcompressed air or a motorized or manually operated air or liquid pump.

The inflation fluid can be air, water, a saline solution or other inertliquid or gas. In some instances, it may be preferable not to use air orother gas in case of malfunction causing the balloon to expandexcessively or burst due to over-pressurization or any other damage.

Advantageously, fitting 312 includes a check valve so that the source ofinflation fluid can be disconnected without anchoring balloon 306becoming deflated. As will be understood, balloon 306 is deflated byopening or removing the fitting 312 from the end of inflation tube 308and, in the case of a liquid inflation fluid, by application of suctionif necessary. As will further be understood, the outer diameter of checkvalve fitting 312 is small enough that it does not interfere withremoval of handle 302 at the end of the planning stage, or insertion ofdelivery tube 308 into the execution stage device as described below.

Alternatively, instead of a balloon, anchoring element 306 may be aresilient expandable element delivered in a compressed configuration ona suitable rod or wire within a covering sheath. For example, anchoringelement 306 may be an expandable cone, or a set of resilient fingers asdescribed in PCT Application IL 2012/050094 published as WO 2012/123950,the content of which is incorporated herein by reference as if fully setforth. Such an anchoring element can be expanded by retraction of itscovering sheath or by being pushed out of its sheath on its deliveryrod, and may be contracted for withdrawal by pulling the delivery rodback into the sheath.

In the illustrated exemplary embodiment, delivery tube 308 is releasablycoupled to planning catheter operating handle 302 as described inconnection with FIGS. 3D-3G below. Consequently, delivery tube 308 andanchoring balloon 306 can be separated from handle 302 and can remain inthe lumen, for example, in case of treatment for BPH, with the balloonremaining in the bladder neck after the planning stage has beencompleted. Alternatively, the execution device may include a separatepositioning device. In such embodiments, the entire planning stagedevice is removed at the end of the planning stage, and a separateanchoring element is provided by the execution stage.

Operating handle 302 is constructed with mechanical features needed onlyfor the planning stage. Alternatively, as previously mentioned, a singleoperating handle can be provided to control the functions of both theplanning stage device and the execution stage device. Separate dedicatedoperating handles may be advantageous in that a dedicated operatinghandle for the planning stage device will be of simpler construction andtherefore less costly, and more convenient for the surgeon to use.

FIG. 3D is a perspective assembly view of the construction of anexemplary planning catheter operating handle 302 with some partstransparent to show internal details, and with planning catheterdelivery tube 308 in place. Planning catheter operating handle 302 iscomprised of a hand grip or pull-handle 330, a pull handle guide 332, acompression spring 334, a tube lock cylinder 336, and a locking screw338. FIG. 3E shows these elements in an exploded view. The configurationof handle guide 332 is shown in FIG. 3F. FIG. 3G is an enlargedperspective view of tube lock cylinder 336, and FIG. 3H is a proximalend elevation of the assembly of FIG. 3D.

The functions of planning catheter operating handle 302 are tofacilitate delivery of anchoring balloon 306 to its position of use, forexample, in the neck of a bladder, and to apply tension through deliverytube 308 to lodge balloon 306 firmly in the bladder neck. This permitsaccurate identification of required implantation sites in conjunctionwith the optical unit of the working channel, and accurate andrepeatable location of the intended implantation sites during theexecution stage.

In the illustrated embodiment, pull handle 330 is comprised of grippingwings 356 a and 356 b, a tubular proximal barrel portion 358 and atubular distal barrel portion 360. Proximal barrel portion 358 includesa longitudinal slot 362 which permits the handle to slide along lockingscrew 338 when the handle is pulled proximally to apply tension asdescribed below.

As shown in FIGS. 3E and 3F, handle guide 332 is a generally tubularstructure comprised of a cylindrical body portion 340 and a cylindricalhead portion 342 having an outside diameter larger than that of bodyportion 342. The interior of body portion 340 is defined by first innerpassage 344 and a smaller internal diameter second inner passage 346,which serves to center delivery tube 308 and tube lock cylinder 336.

The interior of head portion 342 includes a first axial passage 348which is a continuation of passage 346 and a larger-diameter secondaxial passage 350. Passage 350 is sized to receive tube lock cylinder336 (see FIGS. 3D and 3G). Head portion 342 also includes a threadedradial passage 352 that receives tube locking screw 338.

Still referring to FIGS. 3D through 3H, planning catheter operatinghandle 302 is assembled with spring 334 mounted on body portion 340 ofhandle guide 332, and these are positioned within the proximal bodyportion 358 of pull handle 330. Tube lock cylinder 336 is positionedwithin axial passage 350 in handle guide head portion 342 (see FIGS. 3Eand 3G). The tensioning mechanism as a whole is mounted in any suitablemanner within pull handle barrel portion 358.

Referring still to FIGS. 3E and 3G, tube lock cylinder 336 includes aninterior passage 354 and a longitudinal gap formed by a through-slot358. Anchoring element delivery tube 308 is sized to slide freelythrough the interior of tubular portions 344 and 346 of pull handleguide 332 and through interior passage 354 in tube lock cylinder 336.When locking screw 338 is tightened, its end 360 presses on a flattenedportion 361 of tube lock cylinder 336 causing gap 358 to close. Thisallows cylinder 336 to grip delivery tube 308, locking the tube in placerelative to the handle assembly. It will be understood that cylinder 336is formed of a resilient material, for example, stainless steel, so thatit returns to its relaxed position when screw 338 is withdrawn, allowingdelivery tube 308 again to slide freely. Use of the slotted tube lockcylinder may be advantageous as it minimizes the risk that tube 308 willbe damaged when screw 338 is tightened.

Thus, when handle 330 is pulled proximally, slot 362 slides along screw338 and spring 334 is compressed by pull handle barrel portion endsurface 370. Consequently, spring 334 applies pressure against handleguide head end surface 372. With delivery tube 308 locked in handleguide 340 by screw 338, the delivery tube is pulled proximally, causinganchoring balloon 308 to lodge firmly against the inside of the bladderneck.

As will be understood, the more handle 330 is pulled proximally, thegreater will be the tensioning force applied to balloon 308. It willalso be understood, that the tension applied to balloon 308 should bethe same in both the planning and execution stages to permit repeatablelocation of positioning catheter 304 during both stages. To facilitatethis, as shown in FIG. 3D, tensioning markers 374 are provided along thelongitudinal edges of slot 362 and on the execution stage operatinghandle as described below.

As noted above, positioning catheter 304 provides a positional referenceelement relative to which the deployment locations for one or moreimplants are determined during the planning stage. For this purpose, asillustrated in FIG. 3A, delivery tube 308 includes a series ofcircumferential markers, two of which are indicated at 314, spaced atintervals along the tube near its distal end proximally of balloon 306.These are visible using the optical device associated with the workingchannel, and allow the surgeon to reproducibly determine the implantdeployment locations relative to the bladder neck when tension isapplied to delivery tube 308. The spacing between the markers may be inthe range of about 1 mm to about 10 mm for example, about 5 mm.

By way of example, in the case of the anchoring element being a balloon,and for treatment of BPH, during the planning stage, pull handle 330 islocked at a convenient position along balloon delivery tube 308 bytightening screw 338, and anchoring balloon 306 is positioned in thebladder and inflated. Then, using the optical device for guidance, asuitable level of tension is applied by pull handle 330 to lodge balloon306 firmly against in the bladder neck.

Still using the optical unit, the surgeon notes the position closest tothe bladder neck at which an implant should be deployed, as well as theother positions, if any, at which deployment of implants would bedesirable.

After the surgeon has determined the implant deployment locations, theplanning stage is complete. The optical unit is then withdrawn to allowinsertion of the execution stage device. As will be understood, with theoptical unit removed, distal markers 314 can no longer be used to locatethe intended implantation sites. In some embodiments, a set of markers316 located at the proximal end of tube 308 are used for this purpose asdescribed below.

In those embodiments in which planning catheter 306 is reused in theexecution stage, planning catheter operating handle 302 is disconnectedfrom the planning catheter, for example, by loosening screw 338 andsliding the handle in the proximal direction. Accordingly, when theexecution stage device is inserted in the working channel, it ispositioned so that the proximal end of the execution stage planningcatheter is received within it so that it can be used during theexecution stage as described below.

External Features of an Exemplary Execution Stage Device

FIGS. 4A is a side elevation showing some of the operational features ofan exemplary execution stage device 400 in which the operating handle isseparate from the one used for the planning stage device. Executionstage device 400 includes an operating handle 402 that may, for example,be generally pistol-shaped with a barrel portion 438 and a grip portion444. Other external structural features include a retractable outersheath 404, a coupler or adapter 406, for example, a threaded or bayonettype, at the distal end of operating handle 402 for connection to acomplementary fitting on the device serving as a working channel. Theabove-identified parts are formed of suitably strong and rigid metal,for example, aluminum or stainless steel, or a suitable biocompatiblepolymer.

The distal end 466 of outer sheath 404 is shown proximally retracted toa point 466 so that a dilation unit 410 including a dilation balloon412, and a delivery tube 414, a cutter 416, and a delivery tube 475 foran implant release mechanism 422, that are contained within the outersheath to the implantation site are visible. These are described inconnection with FIG. 4B below.

An electrical connector 432 provides an inlet for a source of electricalor electromechanical power, for example, a conventional diathermymachine or a piezoelectric transducer, to provide electrical power tothe blade of cutter 416 that forms an implant-receiving cut. Also, afluid connector 434, for example, a standard Luer type connector, isprovided for connection to a source of inflation fluid for dilationballoon 412 through a fluid conduit 436 and an inflation port describedbelow within handle 402. Preferably, the inflation fluid for balloon 412is a liquid for the reasons stated above.

It will be recalled that in some embodiments, the positioning catheter304 used during the planning stage is coupled to execution device 400for reuse during the execution stage, but that in other embodiments,execution device 400 includes a dedicated planning catheter. Bothsituations are represented by planning catheter 304 shown at the distalend of execution stage device 400, and with the proximal end 435 of itsinflation tube 308 extending out of the proximal end of operating handle402 at 436.

Operating handle 402 also includes actuators for the execution stagefunctions. These include a trigger 428 to operate a mechanism thatrotates a cutter to form an implant-receiving cut on the inner surfaceof the tissue surrounding the constricted area of a 4A bear the samereference signs as in FIG. 4A. lumen, two knobs 424 on opposite sides ofhandle 403 which serve as actuators for the mechanism to retract andextend outer sheath 404, a locking screw 426 for locking the positioningcatheter to the operating handle, a tension indicator 425, and a lever438 that actuates an implant release mechanism. Two knobs 424 areprovided on the opposite sides of operating handle 402 to accommodateuse by the left or right hand.

It should be understood that execution stage device 400 is intended as anon-limiting example, and may include different and/or other structuralfeatures and/or actuators, as well as internal components as describedbelow.

For example, in an unillustrated variation, the operating handle for theexecution stage device may be constructed without a tensioningmechanism. In such an embodiment, the planning stage operating handlewhich contains its own tensioning device can be attached to the proximalend of the execution stage operating handle to provide the requiredtensioning mechanism. Any suitable arrangement for coupling the handlestogether may be employed.

Parts that perform the actual execution stage functions inside the lumenare shown enlarged in FIG. 4B, again for example, in an embodiment inwhich the planning catheter 304 of planning stage device 300 is reusedin the execution stage device. These parts include a dilation unit 410comprised, for example, of a balloon or other expandable element 412mounted on a delivery tube 414, a rotatable cutter 416 comprised, forexample, of a blade 418 and a pusher wire 462 carried for deliverywithin a tube or inner sheath 420, and an implant carrier and releasemechanism 422 comprised for example, of a release pin 468 and a carriertube 475.

Briefly, dilation unit 410 is expanded to enlarge the lumen before orduring deployment of one or more implants. Cutter 416 forms a cut on theinner surface of the tissue surrounding the lumen (for example, theinner surface of the prostate that defines the urethral passage throughthe prostate).

Dilation element delivery tube 414 is comprised of an outer tube 414 aand a concentric inner tube 414 b. The two tubes 414 a and 414 b areformed for example, of stainless steel and are partially welded togethernear their respective distal ends to form a rigid assembly while alsoproviding an annular passage 414 c between the tubes for inflation ofballoon 412. Optionally, the tubes may be partially welded at theirrespective proximal ends as well. Outer section 414 a terminates withinballoon 412 while inner section 414 b extends distally beyond theballoon.

The proximal end of balloon 412 is attached to the outer delivery tubesection 414 a and the distal end of the balloon is connected to innerdelivery tube section tube 414 in any suitable manner usedconventionally for assembly of devices such as balloon catheters. 412.Consequently, the opening at the distal end of outer tube 414 a servesas an inflation port for balloon 412.

Also, as may be seen in FIG. 4B, anchoring balloon delivery tube 308extends through and distally beyond inner tube section 414 b, andtherefore a separate fluid-tight seal around tube 308 is not required.In those embodiments for which planning catheter 304 is reused duringthe execution stage, tube 308 is inserted into tube 414 so that itextends out through the proximal end of operating handle 402 (see FIG.4A).

In some embodiments, cutter 416 is used to form one or moreimplant-receiving cuts in the tissue surrounding the lumen. In someembodiments, implant carrier and release mechanism 422 delivers animplant to the deployment site and includes an element 468, for example,a pin or a rod, operable from the control handle to release the implantfor deployment in the cut formed by blade 418. For convenience, implantcarrier and release mechanism 422 will sometimes be referred to hereinsimply as the “implant carrier”.

Dilation unit 410, cutter 416, implant carrier 422, and an implantpusher assembly (the latter described below in connection with FIGS. 5Nand 5O), are contained within outer sheath 404 during delivery ofexecution device 400 through the working channel to the treatment siteand are exposed when outer sheath 404 is retracted to the position shownat 466 in FIG. 4B, for example, about 10 cm. In this connection, it willbe understood that dilation balloon 412 which is delivered un-inflatedwithin sheath 404, has been shown inflated in FIG. 4B. Similarly, cutterblade 418 which is delivered, inside sheath 420 according to someembodiments, is shown pushed out of the sheath and with blade 418 in itsoperative position extending outwardly toward the tissue surrounding thelumen, as described below.

The components shown in FIG. 4B are formed of suitable biocompatiblematerials. Balloon delivery tube 414 is formed of a rigid material, forexample, stainless steel. Balloon 412 may be formed of nylon or PET.Cutter blade 418 is formed of a resilient metal, for example, nitinol,or stainless steel. Cutter delivery tube 420 and implant carrier 422 maybe formed of a suitable polymer, for example, PEEK, polyethylene,Pebax®, or Nylon®. The parts identified above and their respectiveactuator mechanisms are described in more detail below.

Referring still to FIG. 4B, in some embodiments, cutter sheath 420, andimplant carrier 422 are attached to dilation balloon outer delivery tubesection 414 a, for example, by adhesive or spaced collars up to a fewcentimeters, for example 3-5 cm, from the proximal end of balloon 414.This allows cutter pusher wire 462 and delivery tube 420 to bend toremain in contact with the balloon as it is expanded.

In other (unillustrated) embodiments, cutter delivery tube 420 andimplant carrier 422 are not attached to balloon delivery tube 414, butare delivered as separate units within outer sheath 404. Optionally, thecutter sheath and the implant carrier may be attached together fordelivery.

As will be appreciated, in any of the above-described embodiments, blade418 is be rotated to form the cut around the lumen. In those embodimentsin which cutter delivery tube 420 and implant carrier 422 are attachedto balloon inflation tube 414, the tube itself is rotatable and in turn,rotates the cutter and the implant carrier. If cutter 416 and implantcarrier 422 are not mounted on dilation balloon inflation tube 408, onlycutter tube 420 and implant carrier 422 are rotated.

Rotation may be provided by a suitable mechanism such as described belowwithin operating handle 402 actuated by trigger 428 (see FIG. 4A).Alternatively, the rotation mechanism may be actuated manually by aknob. As another alternative, a motor may be provided in handle 402 toprovide the rotation.

In some embodiments, when balloon 412 is inflated as shown in FIG. 4B,it bears on cutter sheath 420 to press the end 458 of blade 418 againstthe tissue to be cut, thereby to assist in formation of the cut. Inembodiments in which the cutter is rotated by inflation tube 414,balloon 412 also rotates, so cutter sheath 420 does not move relative tothe balloon. This may be desirable as it may protect the balloon frompossible damage due to movement of cutter sheath 420.

However, even those embodiments in which only the cutter and the implantcarrier are rotated, balloon 412 may be sized so that when it is fullyinflated, it bears on sheath 420 so that the edges 454 and 458 of blade418 are pressed against the tissue to be cut to assist in making the cut(see FIGS. 4B and 4D).

FIGS. 4B and the enlarged fragmentary view of FIG. 4C also illustratepart of the implant delivery and release mechanism 422 according to someembodiments. This is comprised of implant release pin 468, the distalend 474 of which forms a projection that engages a small loop 470attached through a hole 471 at one end of an implant 472. Loop 482 issmall enough that it lies within the implant-receiving cut and does notinterfere with the function of the implant.

Pin 468 extends through a tube 475 within outer sheath 404 intooperating handle 402. A retraction mechanism in handle 402 is coupled topin 468, and is operable to pull pin 468 proximately to withdrawprojecting pin end 474 out of loop 470 to release the implant. Likecutter delivery tube 420, implant carrier tube 475 and releases pin 468are sufficiently flexible that they can bend as balloon 412 is expanded.

An exemplary mechanism for retracting release pin 468 is described inconnection with FIG. 5K below.

As shown in FIGS. 4B and 4C, and as described in the previouslymentioned '229 International Application, implant 472 is advantageouslyan open ring, for example, C-shaped, formed of a suitable resilientmaterial.

One advantage of the open-ring configuration, particularly in treatmentof BPH, is that because of the lobular shape of the prostate, it is hardto achieve a full circular cut of a suitable uniform depth. For example,at the “junctions” of the lobes, deeper penetration of the blade may beneeded to help assure that the implant is deployed fully within theprostate tissue, but such deeper penetration may an cause perforation inother areas of the prostate, which may pose a safety issue.

Moreover, the main “junction”, i.e., the area of the greatest variationin the prostate surface is located generally facing the rectum, andorienting the implant so that its opening faces in that direction (andwill not require implantation) increases the probability that theimplant is fully within the prostate and the probability that it will befully covered by a new tissue growth layer without the need for a deepcut and undue risk of perforation.

Open-ring implants may also be desirable in that one size implant may beused for lumens of various internal dimensions.

After balloon 412 is fully expanded, and the implant is released fromsheath 404, the implant rests on the balloon surface but is preventedfrom expanding to its full size because it is still held on pin 468.Advantageously, implant 472 is still at least partially compressed whenit is seated in its cut. This allows the implant to exert radial forceon the lumen to help prevent it from re-collapsing.

It should be appreciated that implant end 469 does not need to berestrained because the implant is delivered rolled up inside sheath 404and it unrolls due to its resiliency when sheath 404 is retracted.

Other constructions arrangements for delivery and release of implant 472are also possible according to some embodiments of the invention. Forexample, in an unillustrated variation, a small pin is mounted on thetrailing end of cutter blade 418. A small hole at the leading edge ofthe implant receives the pin so that the cutter serves as the implantcarrier. As the cutter rotates, the implant follows it into the cut dueto its resiliency. A trigger wire such as that employed in theembodiment shown in FIGS. 4B and 4C separates the implant from thecutter pin when the cut has been completed. It should be appreciatedthat in such an embodiment, the implant itself participates in formationof the cut.

FIG. 4D shows the construction of cutter blade 418 according to someembodiments of the invention, with delivery tube 420 removed. In theillustrated embodiment, blade 418 is a unitary L-shaped element formed,as previously noted, of a resilient material such as nitinol. The bladeincludes a longitudinally extending proximal leg portion 452 and anerectable distal leg portion 454 separated by a flexible area 456 thatfunctions as a hinge. As noted, blade 418 is a single part. It may beformed, for example by laser-cutting and heat-treatment to provide theflexibility to be bent at 456 under pressure and to return to itsoriginal treated structure while pressure is released. This allowsdistal leg portion 454 to be folded back along proximal leg portion 452while inside sheath 420 during delivery. Due to its resiliency, whenouter sheath 404 is retracted, and distal leg 454 is pushed out ofsheath 420, it pops up to the position shown in FIG. 4D, approximatelyat a 90 degree angle.

It has been found that attention to certain features of cutter blade 418will potentially help optimize its performance. In particular, distalleg 454, which is optionally sharpened at its outer edge 458, actuallyforms the cut. However, since the blade is formed of a resilientmaterial such as nitinol, it should be dimensioned to help assure thatthe cut is formed cleanly and with minimum risk of tissue damage.

Taking the foregoing into account, it has been found to be potentiallyadvantageous that the width W of distal blade portion 454 be greatenough in the direction tangential to the cutting direction (indicatedby arrow 460) that it is sufficiently stiff to retain its shape.

At the same time, dimension W should not be so great that, when theblade is folded, the required diameter of delivery sheath 420 and/orouter sheath 404 is so great that insertion of outer sheath 404 into thelumen, for example, through the working channel, becomes a problem.

Further, a wide blade may require higher energy while performing thecut, which can increase the risk of damage to the surrounding tissue. Insummary W should be selected to retain its shape while the cut is beingmade and without risk to damage to surrounding tissue and withoutundesirable enlargement of the diameter of the outer sheath. Taking theforegoing factors into consideration, it has been found that goodresults may potentially be obtained if W is selected within the range ofabout 0.2 mm to about 3 mm, for example, about 0.9 mm.

Other considerations that have been found to be important include thefollowing:

(a) the length of distal blade portion 454 should be selected accordingto the desired depth of cutting. If blade portion 454 is too long; therisk of perforation of the tissue in the cutting area may be increased.On the other hand, if blade portion 454 is too short, the cut may besuperficial, and the entire implant may not be seated in the cut. Thatmay interfere with new tissue overgrowth. Taking the foregoing intoaccount, good results can potentially be achieved if L is selectedwithin the range of 2-20 mm for example 6 mm for treatment of aprostate.

(b) blade portion 454 should be thin to give the blade the flexibilityto be folded into its delivery tube 420 or outer sheath 404 for deliveryand withdrawal. In addition, a thin sharpened edge may require lowerenergy which may require that cutting is also done mechanically (as witha knife). On the other hand, if is too thin, the blade could be deformeddue to thermal effect caused by electrical current during cutting.Taking the foregoing into account, good results can potentially beobtained with a blade thickness T in the range of 0.15-0.3 mm forexample 0.22 mm.

Still referring to FIG. 4D, proximal leg 452 of blade 418 is attached toa pusher wire 462 for example, at several weld points 463 between thelegs of a fork-shaped end portion 461. Pusher wire 462 extends throughinner sheath 420 and outer sheath 404 into operating handle 402 fromwhich it is manipulated by the surgeon to push blade portion 418 out ofsheath 420 for use, and to retract it back into the sheath for removal.It will be appreciated that when blade 418 is retracted, distal leg 454bends in the opposite direction from its delivery position so that it isunfolded and extends linearly within tube 420.

Blade pusher wire 462 is connected to wire 432, which in turn, isconfigured for connection to a source of power for the cutter blade, asdescribed below.

In the illustrated embodiment, there is no need to re-extend outersheath 404 for removal of the components of implantation device 400since cutter blade 418 is withdrawn into sheath 420 (bent in theopposite direction from its delivery orientation) and anchoring balloon306 and dilation balloon 412, when deflated, have smaller diameters thanthe internal diameter of the outer sheath.

Other constructions for delivery of cutter mechanism are possible,according to some embodiments as will be understood by those skilled inthe art in light of the present disclosure. For example, in anunillustrated variation of the arrangement for delivery of cuttermechanism 416 described above, blade 418 and wire 462 are delivered tothe implantation site folded as previously described, without a deliverytube 420, i.e. only in outer sheath 404. When outer sheath 404 isretracted, wire 452 holds it in place longitudinally so that cutterblade 418 pops up to its operative position for withdrawal of theexecution device, wire 452 is pulled proximally and the cutter isretracted into the outer sheath as previously described.

As in the case of the illustrated embodiment, there is no need tore-extend outer sheath 404 for removal of the components of executiondevice 400. However, it may be advantageous for cutter 416 to beretracted into sheath 404 so that cutting edge 458 does not contact anddamage the inside of the working channel device.

In the illustrated example, dilation element 412 is a generallycylindrical balloon having a length in the range of about 0.5 cm. toabout 5 cm. for example, 1.5 cm, and an inflated diameter in the rangeof about 1-50 mm, for example, 20 mm.

Alternatively, in an unillustrated variation dilation unit 410 can beformed of a plurality of smaller diameter balloons of generallycylindrical shape positioned in a circumferential ring around deliverytube 414. In such embodiments, dilation elements 440 may include between2 and 10 separate balloons, for example 6 balloons, each having aninflated diameter in the range of about 1 mm to about 25 mm, forexample, 10 mm. The length of the individual balloons 440 may be thesame as that of balloon 412.

In some multiple-balloon embodiments, inflation/delivery tube 408includes a manifold 442, for example a branched tube, at its distal endto inflate the balloons. Alternatively, each balloon may have its owninflation tube.

Multiple small balloons may be advantageous in some instances since itmay be possible to use off-the-shelf items. Using a plurality of smallballoons may also reduce the effect of balloon malfunction—if a singleballoon is damaged or has a leak, the effectiveness of the dilation willnot be significantly reduced.

On the other hand, a single balloon may be easier to design, simpler toassemble, and may give a smoother expansion of the urethral tissue andtherefore may improve cutting performance.

The cut for the implant is formed preferably using electrical energyprovided, for example, by a conventional diathermy machine or apiezoelectric transducer through a connector wire 432 extending throughgrip 444, as shown in FIG. 4A.

As a further option, in some embodiments, the implant itself isconnected directly to the source of electrical energy so that it formsits own cut, e.g., by rotation on the surface of a rotatable dilationballoon or simply by radial expansion when the dilation balloon isinflated. In the latter case, the implant effectively “burns” its wayinto the wall of the tissue surrounding the lumen, and a separate cutterunit is not needed. Optionally, the implant may include a sharp edge tofacilitate formation of the cut if the implant can rotate.

Several options for the construction and configuration of cutter 416 areshown in International Published Application WO 2012/123950, the contentof which is incorporated herein by reference as if fully set forth.

Internal Construction of an Exemplary Execution Device Operating Handle

FIG. 5A is a side elevation showing some of the operating features of anexemplary embodiment of operating handle 402, and with some partstransparent to show internal details. In the illustrated embodiment,handle 402 is formed of a body 500 on which the internal components aremounted and a side cover 490. FIG. 4A shows side cover 490 in place,while FIG. 5A shows the side cover removed to reveal the internalconstruction. FIG. 5B is a top view of operating handle 402 with lockingknob 426 removed. For clarity, the components shown in FIGS. 5A-5Cpreviously discussed in connection with Fig

Parts located within operating handle 402 include a tensioning mechanism502 for positioning catheter delivery tube 308, an external sheathretraction mechanism 504, a cutter rotation mechanism 506 including aconnection of blade pusher wire 462 to power connector wire 432 aspreviously described in connection with FIGS. 4A and 4D, a dilationballoon inflation port 508, an implant release mechanism actuator 510.Handle 402 also includes an implant pusher mechanism 520 shown in FIGS.5N and 5O. The components shown in FIG. 5A and 5C are mounted in anysuitable and desired manner in body 500, as will be apparent to thoseskilled in the machine design arts in light of the disclosure herein.

FIGS. 5A and 5B also show previously described external parts ofoperating handle 402 including external sheath 404, sheath retractionactuator knobs 424, locking knob 426 for positioning catheter deliverytube 308, cutter rotation trigger 428, cutter electrical connector 432,dilation balloon inflation tube 436, and implant release mechanismhandle 438.

FIG. 5C is a perspective view of operating handle 402 enlarged toemphasize exemplary construction of some of the parts shown in FIG. 5A,including tensioning mechanism 502, external sheath retraction mechanism504, cutter rotation mechanism 506, dilation balloon inflation port 508,and implant release mechanism actuator 510 according to someembodiments.

The component parts of tensioning mechanism 502 are shown in an explodedview in FIG. 5D. The construction of tensioning mechanism 502 is largelythe same as that of planning stage device tensioning mechanism 302illustrated in FIGS. 3E-3G, including a handle guide 512, a compressionspring 514, a tube lock cylinder 516, and a lock knob 525, which are ofthe same construction as corresponding parts 332, 334, and 336,respectively. Tensioning mechanism 592 also includes a marker pointer518, and tension is applied by pulling on operating handle 402 ratherthan by pull handle 330.

The distal end of spring 514 is restrained by a collar, half of which isformed in handle body 500 and shown at 522 in FIG. 5C, and the otherhalf of which is formed in a complementary position in handle cover 490.

As in the case of the tensioning mechanism described in connection withplanning stage device 300, tensioning mechanism 502 is used to apply aselected repeatable tension to catheter delivery tube 308. The appliedtension is advantageously approximately the same as that applied toanchoring balloon delivery tube 308 during the planning stage so thatthe proximal markers 316 on delivery tube 308 can on used to locatedilation balloon 412 and cutter 416 properly during the execution stage.Thus, using the proximal markers 316 as a guide, handle 402 is locked toanchoring balloon shaft 308 at the position determined during theplanning stage. In this connection, it should be recalled that thepositions of the proximal and distal markers are correlated since theshaft length is fixed. The distance between every two correlated markersis the total distance between the blade and the end of the handle, whichis always fixed.

FIG. 5E is a perspective view of marker pointer 518. This is comprisedof a tubular body 524 having an internal passage 526 that receives shaft524 of locking knob 525, and a pair of wings 528 a and 528 b withpointing elements 530 a and 530 b at their respective lower ends.

FIG. 5F is an enlarged perspective view showing the way that pointers530 a and 530 b are used according to some embodiments of the invention.As illustrated, body 500 and cover 490 include cut out areas the form achannel 522 when the two external parts are fitted together within whichlock knob shaft 524 slides when handle 402 is pulled proximally. Aseries of tension markers 523 are provided along the both sides ofchannel 522 which cooperate with pointer elements 530 to indicate thetension.

Other ways to help the surgeon apply the same tension during theexecution stage as was applied during the planning stage are alsopossible within the scope of the invention. In an embodiment illustratedin FIG. 5G, tension markers 523 and pointers 530 are not needed toindicate the required execution stage tension. In this embodiment, apressure sensing device 590 is connected between positioning catheterdelivery tube 308 and a source of inflation fluid 592. Pressure sensor590 is connected to a pressure recording and indicating device 594 whichoperates to record the pressure on anchoring balloon 306 as a result oftension applied during the planning phase and to provide a visual and/oraural indication when the same tension is applied during the executionstage.

This functionality may be better understood by recognizing that in boththe planning and execution stages, when anchoring balloon is fullyinflated, but no tension is being applied the pressure measured bysensor 590 is a fixed value P₀, for example, 50 mm Hg. When tension isapplied, however, balloon 306 is pressurized to an increased pressure ΔPresulting from the tension force. Since it is desired for ΔP to beapproximately the same in the planning and execution stages, pressureindicator 594 can be constructed to record the selected inflationpressure and ΔP during the planning stage, and to provide a visualindication and/or an aural indication such as a tone. The surgeonmaintains the tension so that ΔP remains substantially constantthroughout the execution stage.

Alternatively, pressure indicator 594 can include an adjustmentmechanism to permit pre-selection of a desired tension. This can beindicated to the surgeon during both the planning and execution stages.It is to be expected that a suitable tension will vary from patient topatient. This can be determined visually at the beginning of theplanning stage using the working channel optical unit.

To relieve the surgeon of the need to maintain the tension during theexecution stage by hand in either of the embodiments described, anattachment may be provided on the surgical table to hold handle 402 in afixed position after the tension has been applied.

The construction of an exemplary external sheath retraction mechanism504 is shown in FIGS. 5H (a side view) and 5I (a distal end view).Mechanism 504 is comprised of a rack 532, a rack cylinder 534, controlknobs 424, spur gear 536, a gear shaft 538, and plungers 540. Rack 532is attached at its distal end 542 to rack cylinder 534 which isattached, for example, by laser welding or adhesive, on external sheath404.

Control knobs 424 and spur gear 536 are mounted on gear shaft 538 sothat counter-clockwise rotation of either knob will retract externalsheath 404, i.e., proximally. A return spring 544 attached at one end tothe handle body and at its other end to cylinder 534 applies tension tofacilitate re-extension of the sheath (see also FIG. 5A).

Referring still to FIGS. 5H and 5I, it may be seen that that rackcylinder 534 includes a vertical projection 535 a, and twosideward-extending projections 535 b and 535 c, Projection 535 a extendsoutward in a slot 537 in the top of the body and side cover of operatinghandle 402 (see FIG. 5B) and serves as an indicator for the position ofexternal sheath 402 while being retracted and extended. This allows theoperator to know that the sheath has been fully retracted when indicator535 a is at the proximal end of its slot 537. Correspondingly, whensheath 404 is being re-extended, full extension is indicated whenindicator 535 a is at the distal end of slot 537.

Sideward projections 535 b and 535 c provide a mounting arrangement forcylinder 534 and for the proximal end of outer sheath 404. Projections535 b and 535 c slide in dedicated slots in handle body 500 and cover490 (not shown) as sheath 404 is retracted and extended. As will beappreciated, the distal end of the slot 537 also serves as a stopper forre-extension of the sheath.

For reference and orientation relative to FIGS. 4A and 4B, FIG. 5H alsoshows cutter delivery tube 420, implant release pin tube 575, anddilation balloon delivery tube 414.

The construction of an exemplary cutter rotation mechanism 506 is shownin FIG. 5A. Cutter rotation mechanism 506 is comprised of a gear segment546 mounted on rotation trigger 428, a transmission gear arrangementcomprising coaxially mounted spur gears 548 and 550, and a pair of bevelgears 552 and 554, the latter being mounted on dilation balloon deliverytube 414.

Pulling on trigger 428 causes dilation balloon inflation tube 414 (andattached cutter tube 420 and implant carrier tube 422) to rotate in theclockwise direction (relative to the proximal end).

Referring still to FIG. 5A, and also to FIG. 4D, it will be recalledthat blade pusher wire 462 is connected to a source of power such as adiathermy machine or a piezoelectric transducer. In an exemplaryembodiment, power cable 432 passes through operating handle 402 and isloosely coiled around dilation balloon tube 414 at 579

A return spring 536 is connected between handle body 500 and electricalwire 432 so that as the wire unwinds while the blade is rotating,tension is maintained on the wire.

As described in connection with FIG. 4B, dilation balloon inflation tube414 is comprised of two concentric tube sections 414 a and 414 bpartially welded at least near their respective distal ends (andoptionally near their proximal ends as well) .to provide an annularinflation fluid passage 414 c through which balloon 412 is inflated.FIG. 5J illustrates the construction of an exemplary dilation ballooninflation port 508 in a side elevation with portions transparent to showinternal parts. Inflation port 508 is comprised of a body 556, aninternal tubular section 558 coupled to inflation tube 436, and endsections 560 a and 560 b. Within end section 560 a is a fitting 561 athat terminates in a fluid-tight (i.e., both gas and liquid tight)coupling element 562 a. Similarly, within end section 560 b is a fitting561 b that terminates in a fluid-tight coupling element 562 b. Couplingelement 562 a is rotatably sealed around dilation balloon inflation tubeouter section 414 a which terminates inside body portion 558. Couplingelement 562 b is sealed around inflation tube inner section 414 b whichextends distally beyond coupling element 562 b. This allows tubesections 414 a and 414 b to rotate within the respective seals withoutleakage of inflation fluid provided to annular passage 414 c. As mayalso be seen in FIG. 5J, anchoring balloon inflation tube 308 passesthrough inner tube section 414 b, and is held in place by locking screw426 comprised in tensioning mechanism 502 as described above (see FIGS.5C and 5D). Consequently, no seal is needed around inflation tube 308

The construction of an exemplary implant release mechanism 510 (seeFIGS. 5A and 5B) is shown in enlarged views in FIGS. 5K-5M Implantrelease mechanism 510 is comprised of a release trigger 566, a releaseflange 568, both formed of a suitable material, for example, ABS,stainless steel, polycarbonate, Implant release mechanism also includespin 468, the latter being located within tube 475 (see FIGS. 4B and 4C).Release trigger 566 is shown in an enlarged perspective view in FIG. 5L.Release flange 568 and carrier tube 475 are shown in an enlargedperspective view in FIG. 5M.

Release trigger 566 is comprised of an upstanding finger pull 570mounted on a slide plate 572 and a body portion 574 terminating in apair of downwardly depending fingers 576 forming an arcuate opening 578that fits between flange rings 580 a and 580 b on release flange 568. Anadditional ring 580 c cooperates with ring 580 b to serve as a spoolaround which power wire coil 579 is wound, as previously noted.

Implant release pin 468 and cutter pusher wire 462 extend throughrelease flange ring 580 b and are attached to it, for example, by asuitable adhesive at 561 a and 561 b, respectively. Power connector wire432 is attached to blade pusher wire 462 at 561 b.

Alternatively, in some embodiments, release pin 468 and cutter pusherwire 462 can be attached to separate flange rings. In other embodiments,pusher wire 462 is not connected to the release flange.

Release flange 568 is slidable on dilation unit delivery tube 414, oncutter delivery tube 420 and on implant release tube 475 so that pin 468and cutter blade 418 can be pulled proximally by trigger 566 to decouplethe projecting end 474 of implant release pin 468 from the implant (seeFIGS. 4B and 4C) and to retract cutter blade 418. Retracting both pinprojection 474 and cutter blade 418 can be advantageous in some casessince it allows cutter blade 418 to be pulled proximally at the sametime the implant is released to help assure safe retraction of theentire delivery system.

Referring again to FIG. 5B, it may be seen that finger pull 570 extendsout of a slot 571 defined by cut out portions of handle body 500 andhandle cover 490 for convenient access.

FIGS. 5N and 5O show side and perspective views, respectively, of anexemplary implant delivery pusher mechanism 523 according to someembodiments of the invention. Pusher mechanism 523 helps assure ejectionof the implants from external sheath 404 (see FIG. 5C). Since theimplant is delivered rolled up inside sheath 404, it presses against theinside of the sheath, and the resulting friction impedes the release ofthe implant when the outer sheath is retracted. Pusher mechanism 523applies a distally directed force on the implant which helps prevents itfrom remaining within outer sheath 404 when the sheath is retracted.

Implant pusher assembly 523 in the illustrated exemplary embodiment iscomprised of a pusher tube 582, an implant pusher 584 that engages animplant 586 rolled up for delivery shown in FIG. 5O, and a pusher flange588, all of which are delivered to the implantation site within outersheath 404 as previously explained. Implant pusher 584 is attached atits proximal end to the distal part of the pusher tube 582 and is thepart that actually engages the implant to push it out of sheath 404.

Referring to FIG. 5O, pusher flange 588 includes two sidewardprojections 588 a and 588 b that are slidably mounted in tracks on thehandle body and the cover, and which provide support for the proximalend of the pusher mechanism.

Representative Method Embodiments

FIGS. 6A and 6B are a flow chart that illustrates an exemplary method oftreating a constricted lumen such as a urethra using exemplary planningand execution stage devices 300 and 400 according to the two-stagemethodology as well as some variations in the method according todifferent embodiments of the invention.

Preliminarily, is should be noted that the parts of the system describedherein may be made available in several different combinations and/orconfigurations. For example, a kit may be provided comprising oneplanning stage operating handle and a plurality of planning catheters.In such an arrangement, the operating handle should be constructed ofmaterials that can be sterilized for reuse.

In some embodiments, the execution stage device may be provided in a kitincluding a single operating handle and a plurality of deploymentsub-units each comprised of a dilation device, one or more cutters, oneor more implants, and an implant release mechanism. As will beunderstood, in such an arrangement, the execution stage operating handlewill be designed for convenient coupling to the deployment sub-unit.Various options for coupling the two units are possible within the scopeof the invention.

Bearing the foregoing in mind, referring to FIG. 6A, at 600, inpreparation for the procedure, a device, for example, a conventionalcystoscope or resectoscope in the case of treatment of a urethra isinserted through the lumen to provide a working channel. The device willusually include an optical unit suitable for viewing the interior of thelumen.

At 602, the planning device 300 is inserted through the working channel,At 604, the anchoring element, for example, balloon 306 or othersuitable anchoring element is positioned and expanded to preventmovement of the positioning device. As noted above, in the case oftreatment of BPH, the anchoring element may be positioned in the neck ofthe bladder as observed using the previously inserted optical unit.

At 606, locking element knob 338 is tightened to unite the planningcatheter to the operating handle, and tension is applied to firmly seatthe anchoring element. In this connection, it should be understood thatin some embodiments designed for treatment of lumens other that aurethra, it may not be necessary to apply tension to the anchoringelement. In embodiments specifically dedicated to such applications, itmay be possible to omit the tensioning mechanism from the planningdevice operating handle and also from the execution device operatinghandle.

At 608, the optical device is used to identify one or moreimplant-deployment locations using the distal markers 314 on deliverytube 308 as a reference.

Optionally, in some embodiments, at 610, where necessary to permitwithdrawal of the optical unit, anchoring element 306 is contracted, andat 612 operating handle 302 is separated from planning catheter 304 byloosening knob 338 sufficiently to disconnect delivery tube 308 fromhandle guide 332.

At 614, the optical device is withdrawn through the working channel. Inthose embodiments in which the planning catheter is left in place, anddoes not need to be contracted to permit withdrawal of the optical unit,610 is omitted, and the process goes directly from 608 to 612.

As another option, at 616, in embodiments in which execution stagedevice 400 includes a dedicated planning catheter, planning stagecatheter 304 is withdrawn entirely. In such embodiments, anchoringelement 306 is contracted and planning stage device 300 is withdrawnthrough the working channel by pulling handle 302 proximally withoutloosening locking screw knob 338. Since delivery tube 308 remainsconnected to handle guide 332 but anchoring balloon 306 has beendeflated, the positioning catheter can easily be withdrawn through theworking channel.

Referring now to FIG. 6B, at 618, if planning catheter 304 is to bereused with the execution stage device 400, it will typically be left inplace in the lumen (whether contracted or left expanded) and is coupledto execution stage operating handle 400 by insertion of its proximal endthrough inner tube 414 b of dilation device delivery tube 414.

At 620, if the planning stage planning catheter is reused but has beencontracted, it is re-expanded. In the embodiments in which executionstage device 400 includes its own positioning catheter, the dedicatedanchoring element of execution device 400 is expanded.

At 622, the planning catheter is positioned at the proximal markercorresponding to the first implant deployment location, locked in place,and tension is applied, if applicable to treatment of a particularlumen.

At 624, outer sheath 402 is retracted, and the cutter, the dilationballoon, the implant, and the implant release mechanism are exposed. At626, if the cutter nit is carried in a separate inner sheath, is alsopushed out of the inner sheath. Pusher assembly 523 is used to assurethat the implant(s) are released when the outer sheath is retracted.

At 628, the dilation balloon is inflated to expand the lumen. At 630,the cutter is operated to form the cut for receiving the implant. At632, the implant is released for deployment in the cut.

At 634 the dilation balloon and the anchoring balloon are deflated.

At 636 the cutter is retracted into its delivery tube or into the outersheath (in embodiments that do not employ a separate delivery tube), andat 638, the execution unit and the anchoring balloon and its deliverytube are withdrawn through the working channel.

At 640, 620-638 are repeated for additional implant(s) if required andare not deployed simultaneously.

Finally, at 642, the working channel is withdrawn.

According to some embodiments, it may be advantageous under certaincircumstances, to remove the implant(s) after a period of time, or toform them of a biodegradable material. This may be desirable, forexample to reduce inherent risks of permanent implantation of anystructure in the body. It has been found that even temporary presence ofan implant inside an incision force the tissue surrounding the lumen torecover in a reshaped way—actually distorting the original shape of thetissue to maintain the patency of the lumen even after implant removal.The resulting “scar” associated with the implantation has negligibleeffect.

FIG. 7A shows the planning catheter 308 extending out of the distal end700 of a cystoscope 702 and extended out of its sheath 310 (See FIG. 3A)with anchoring balloon 306 inflated through delivery tube 308, as itwould appear at the completion of method element 604

FIG. 7B shows the configuration of the distal end of execution device400 (See FIG. 4A) installed over anchoring balloon delivery tube 308with outer sheath 402 in its delivery configuration extending out of thedistal end 700 of cystoscope 702, and with anchoring balloon 306inflated. This is the situation after method element 614.

FIG. 7C shows the distal end of execution device 400 after retraction ofouter sheath 402 with dilation balloon 406, cutter unit 410, and implant414 exposed but before inflation of balloon 406 after completion ofmethod element 624 (and 626 if an inner sheath is employed).

FIG. 7D shows dilation balloon 406 inflated, but before the cut has beenformed in the prostate, corresponding to method element 628.

FIG. 8 shows in highly schematic form one option for deployment ofmultiple implants according to some embodiments. Here, the executiondevice carries three implants 800, 802, and 804 and three cutters 806carried by a delivery tube indicated schematically at 808 and mounted ona dilation balloon 810. In this situation, cuts would be performed forall three implants simultaneously (at 630) released simultaneously (at632) a release mechanism (not shown for clarity) and no repetition (at640)

Although FIG. 8 illustrates three implants, a larger number, forexample, four, five or even more may be provided. In some embodimentsthe spacing between the implants is fixed. In some embodiments thespacing may be adjusted before delivery to the treatment site accordingto observations made during the planning stage.

According to another option, several implants may be deployedsuccessively using separate execution devices. In this case, methodelements are repeated as many times are necessary to deploy all therequired implants (at 640). Typically, a separate execution device wouldbe used for each successively deployed implant. Optionally, the sameoperating handle is used each time.

General Comments

It will be appreciated that other constructions for the functionalfeatures of operating handles 302 and 402 are also within the scope ofembodiments of the invention. For example, the locking elements for thetensioning mechanisms can comprise lever-operated or twistable cam locksor over-centering mechanisms to engage the locking cylinder. Likewise,constructions other than those shown and described for the operatingfeatures of the execution stage operating handle are also possiblewithin the scope of the invention.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives,modifications, and variations will be apparent to those skilled in theart. Accordingly, it is intended to embrace all such alternatives,modifications, and variations that fall within the spirit and broadscope of the appended claims.

Specific features comprised in a described embodiment are to beconsidered as exemplary of that embodiment. The described embodimentshould not necessarily be construed to require the feature and thefeature should be regarded as suitable for inclusion in otherembodiments unless otherwise clearly indicated.

The terms “comprises”, “comprising”, “includes”, “including”, “having”and their conjugates mean “including but not limited to”. This alsoencompasses the terms “consisting of” and “consisting essentially of”.

As used herein, the singular form “a”, “an” and “the” include pluralreferences unless the context clearly dictates otherwise. For example,the term “an element” or “at least one element” may include a pluralityof elements. The word “exemplary” is used herein to mean “serving as anexample, instance or illustration”. Any embodiment described as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments and/or to exclude the incorporationof features from other embodiments. The word “optionally” is used hereinto mean “is provided in some embodiments and not provided in otherembodiments”. Any particular embodiment of the invention may include aplurality of “optional” features unless such features conflict.

Throughout this application, various embodiments of this invention maybe presented in a range format. It should be understood that thedescription in range format is merely for convenience and brevity andshould not be construed as an inflexible limitation on the scope of theinvention. Accordingly, the description of a range should be consideredto have specifically disclosed all the possible sub-ranges as well asindividual numerical values within that range. For example, descriptionof a range such as from 1 to 6 should be considered to have specificallydisclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numberswithin that range, for example, 1, 2, 3, 4, 5, and 6. This appliesregardless of the breadth of the range.

As used herein the term “method” refers to manners, means, techniquesand procedures for accomplishing a given task including, but not limitedto, those manners, means, techniques and procedures either known to, orreadily developed from known manners, means, techniques and proceduresby practitioners of the relevant technological arts.

As used herein, the term “treating” includes abrogating, substantiallyinhibiting, slowing or reversing the progression of a condition,substantially ameliorating clinical or aesthetical symptoms of acondition or substantially preventing the appearance of clinical oraesthetical symptoms of a condition.

It should be appreciated that certain features of the invention, whichare, for clarity, described in the context of separate embodiments, mayalso be provided in combination in a single embodiment. Conversely,various features of the invention, which are, for brevity, described inthe context of a single embodiment, may also be provided separately orin any suitable subcombination or as suitable in any other describedembodiment of the invention.

Certain features described in the context of various embodiments are notto be considered essential features of those embodiments, unless theembodiment is inoperative without those elements.

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present invention. To the extent thatsection headings are used, they should not be construed as necessarilylimiting.

1. A system for treatment of a urethra that is constricted due to BPHcomprising: a positioning device including a positioning guide visibleoutside the urethra for determining the location of the area to betreated an execution device for executing the treatment comprising: adilation unit including an expandable element positionable to enlargethe urethra in the area to be treated and a delivery shaft connected tothe expandable element; a cutter including a blade positionable to forma cut in the inner surface of the tissue surrounding the area to betreated as indicated by the positioning device; and an implant carrierreleasably connectable to an implant for delivery to the area to betreated including a shaft operable to release the implant into the cut;wherein the dilation unit is operable before release of the implant. 2.A system according to claim 664, wherein the second positioning guidecomprises spaced markings configured to be visible using an opticaldevice inserted in the urethra.
 3. (canceled)
 4. A system according toclaim 66, wherein the anchor and the expandable element of the dilationunit are balloons and the delivery shafts for the balloons include fluidpassages connectable to a source of inflation fluid to expand theballoons.
 5. (canceled)
 6. A system according to claim 4, wherein theanchor balloon is substantially toroidal in shape upon inflation.
 7. Asystem according to claim 1, wherein the dilation unit delivery shaft iscomprised of two concentric tubes partially attached together at leastdistally, the fluid path being defined by a substantially annularpassage between the two tubes.
 8. A system according to claim 66,wherein the anchor and the dilation element are self-expanding, and thedelivery shaft for each is configured to release the respectiveself-expanding elements for expansion.
 9. A system according to claim 1,wherein the cutter includes the implant carrier.
 10. A system accordingto claim 1, wherein the implant carrier is comprised of an elongatedpin, the pin including a projection at its distal end sized andpositioned to engage a hole or a loop at one end of an implant and anactuator configured to pull the pin proximally to disconnect the implantfrom the projection. 11-12. (canceled)
 13. A system according to claim1, wherein: the cutter blade is delivered to the treatment arearetractable outer sheath; the cutter is rotatable; the cutter blade isformed of a resilient material and is comprised of a proximal portionand a distal portion; upon retraction of the outer sheath, the bladeassumes an operating configuration with its distal end in contact withthe surface of the prostate tissue surrounding the urethra to form a cutas the cutter is rotated.
 14. (canceled)
 15. A device according to claim13, wherein the cutter further comprises a delivery tube for the bladeand a pusher-wire coupled to the proximal end of the blade to push itdistally out of its delivery tube so that it assumes its operatingconfiguration and to pull the blade proximally to retract the blade backinto the delivery tube for withdrawal of the execution device from thelumen. 16-20. (canceled)
 21. A system according to claim 66, wherein thepositioning device anchor and its delivery shaft are configured to becoupled to the execution device during treatment or the execution deviceincludes a dedicated anchor and delivery shaft. 22-23. (canceled)
 24. Asystem according to claim 1, wherein the positioning and executiondevices are integrated in a single unit. 25-29. (canceled)
 30. A systemaccording to claim 1, wherein: the dilation unit is rotatable; and theimplant carrier, the implant release mechanism, and the cutter arecoupled to the dilation unit and are rotatable thereby. 31-33.(canceled)
 34. A system according to claim 1, further comprising anoperating handle for the execution device comprising: a mechanismconfigured to retract an outer sheath; a mechanism configured to push animplant out of the outer sheath; a gear assembly including an actuatorto rotate the cutter; and a mechanism configured to release an implantfrom the carrier.
 35. A system according to claim 4, further comprisinga pressure sensor connectable to the inflation tube for the anchor; anda pressure indicator, wherein the pressure indicator is responsive tothe pressure in the anchor inflation tube when tension is applied duringthe planning stage to provide a visual and/or aural indication when thesame pressure is applied while locating the area of treatment and duringexecution of treatment.
 36. (canceled)
 37. A system according to claim30, further comprising an operating handle for the execution deviceincluding an inflation port configured to provide inflation fluid forthe dilation balloon while the dilation unit rotates.
 38. The systemaccording to claim 37, wherein the inflation port comprises: a body; atubular passage, wherein one end of the passage is coupled to the bodyand the other end terminates in a fitting connectable to a source ofinflation fluid; and end sections on proximal and distal ends of thebody including portions formed of a resilient material, wherein: thedistal end section is coupled to the dilation unit inflation tube andprovides a fluid-tight rotatable seal for the dilation unit inflationtube.
 39. A system according to claim 1, further including a mechanismfor closing the implant-receiving cut by application of an adhesive, orby a clamp, or by a suture.
 40. A method for treating a urethra that isconstricted due to BPP comprising: identifying a constricted area of theurethra requiring treatment; using a transurathrally inserted executiondevice, delivering a substantially C-shaped implant in a compressedcondition for deployment at the treatment area; expanding the urethra inthe treatment area; forming a cut in the inner surface of the prostatesurrounding the constricted area; and inserting the implant into the cutafter the urethra has been expanded with an open portion facing therectum wall to maintain the expansion of then urethra.
 41. A methodaccording to claim 40, wherein forming the cut includes connecting acutter to a diathermy machine or a piezoelectric transducer to provide asource of electrical or electromechanical energy and rotating the cutteraround an inner surface of the prostate tissue surrounding an area ofthe urethra requiring treatment.
 42. (canceled)
 43. A method accordingto claim 40, further comprising removing the implant after apredetermined time, or wherein the implant is formed of a material thatis biodegradable. 44-49. (canceled)
 50. A method according to claim 68,wherein the anchor and an element for expanding the urethra areballoons, and the balloons are inflated using a liquid as an inflationfluid.
 51. A method according to claim 68, further including connectingthe positioning device to the execution device for use during thetreatment.
 52. A method according to claim 40, further comprising:delivering two or more implants to the area to be treatedsimultaneously; forming cuts for all of the implants simultaneously, anddeploying all of the implants simultaneously.
 53. A method according toclaim 40, wherein two or more implants are delivered simultaneouslyusing a single unit for delivery of all the implants or delivering eachimplant separately, and further comprising forming cuts for the implantsat the time the respective implants are delivered. 54-57. (canceled) 58.The method according to claim 40, wherein the cut is formed by a cutterdelivered to the implantation site, or by the implant, or by cooperationof a cutter and the implant.
 59. The method according to claim 40,further including closing the implant-receiving cut after deployment ofthe implant by application of an adhesive, or by a clamp, or by asuture. 60-64. (canceled)
 65. An execution device for a system fortreatment of a constricted intrabody lumen comprising: a dilation unitincluding an expandable element to enlarge the lumen in an area to betreated; an implant carrier to releasably deliver an implant to the areaof the lumen to be treated as identified during a preliminary planningstage of the treatment; a cutter including a blade positionable to forma cut in the inner surface of the tissue surrounding the area to betreated to receive the implant by application of electrical orelectromechanical energy to the tissue; and a release mechanism forseparating the implant from the implant carrier.
 66. Apparatus accordingto claim 1, wherein the positioning device includes: an anchor shapedand sized to lodge in the neck of a bladder; an elongated delivery shaftinsertable transurathrally connected to the anchor; and a secondpositioning guide at the distal end of the anchor delivery shaft forvisually determining the location of the area to be treated beforetreatment is executed.
 67. Apparatus according to claim 66, wherein thesecond positioning guide is comprised of spaced reference marksextending proximally along the anchor delivery shaft from adjacent tothe positioning device anchor and the treatment positioning guidecomprises spaced reference marks at the proximal end of the anchordelivery shaft wherein the proximal and distal markers are positionallycorrelated.
 68. A method according to claim 40, wherein the one or moreareas requiring treatment are identified by: transurathrally inserting apositioning device into the urethra, the positioning device including ananchor and an anchor delivery shaft; anchoring the positioning device inthe neck of the bladder; inserting an optical device into the urethra;and visually identifying a desired location for forming the cut relativeto spaced markings extending proximally on the anchor delivery shaftfrom adjacent to the anchor.
 69. A method according to claim 68, whereinthe cut is performed using a cutter that is positioned at the time oftreatment relative to a second set of spaced markers located at theproximal end of the anchor delivery shaft that are located outside theurethra and and are positionally correlated with the set of markers atthe distal end of the anchor delivery shaft.